What is the method that hot galvanization adds aluminium to zinc pot to have?
In order to keep 0.10 ~0.2% aluminum in the zinc solution, a certain amount of aluminum must be added to the zinc pot. To sum up, there are three ways to add aluminum to the zinc pot:
(1) addition of pure aluminum: aluminum ingots (cut into 1~2 kg) are pressed under the zinc liquid level in a certain shape to slowly melt under the corrosion of zinc liquid. This method can save the alloy refining process, reduce the zinc particle defects of finished products, avoid excessive oxidation of aluminum and save aluminum.
(2) zinc-aluminum binary alloy: in a special alloy furnace, zinc-aluminum alloy containing 7~15% aluminum is processed and cast into about 8Kg alloy ingots.Generally speaking, zinc-aluminum alloy ingots containing 8% aluminum are the most suitable, because when the aluminum content is high and the specific gravity is light, the alloy floats at the zinc liquid level and melts slowly, which is easy to cause excessive oxidation of aluminum and accelerate the consumption of aluminum. In the production process, zinc-aluminum ingots and zinc-ingots are added to the zinc pot in proportion.
(3) add aluminum zinc ingots: in hot galvanizing, zinc pot contains 0.10 ~ 0.15% aluminum, but also contains 0.24% lead, in order to simplify the operation of zinc pot procedures and reduce the oxidation of aluminum waste, has been developed for the use of aluminum, lead content of zinc ingots.Production directly put the zinc ingot in zinc pot, but in the actual production, due to the actual aluminum consumption is more than double that of aluminum content in liquid zinc, so although have liquid aluminum and zinc content from the same contain aluminum zinc ingot, also must be prepared to aluminum content is 5 ~ 8% of zinc - Al binary alloy ingot, to join the zinc pot, to maintain a constant aluminum content in the pot.